Washington, US President Donald Trump on Wednesday said he had hosted successful talks in the White House with representatives of Egypt, Ethiopia and Sudan on a controversial dam being built on the Nile.

Trump was mediating in a dispute over Ethiopia's construction of the huge dam which Egypt says could drastically disrupt the Nile, the river providing 90 percent of the country's drinking water.

"Just had a meeting with top representatives from Egypt, Ethiopia, and Sudan to help solve their long running dispute on the Grand Ethiopian Renaissance Dam, one of the largest in the world," Trump tweeted.

"The meeting went well and discussions will continue during the day!" he added.

A US official said in October that President Abdel Fattah al-Sisi had asked Trump to get involved in the dispute when they met in September on the sidelines of the UN General Assembly.

The Nile is a lifeline supplying both water and electricity to the 10 countries it traverses.

Its main tributaries, the White and Blue Niles, converge in Sudanese capital Khartoum before flowing north through Egypt to drain into the Mediterranean Sea.

Analysts fear the three Nile basin countries could be drawn into a conflict if the dispute is not resolved before the dam begins operating. It is scheduled to go online by 2022.

Discussions between the three countries broke down this year prompting Egypt to call for international mediation last month.

Sisi described Trump as being of "unique standing with the power in dealing with conflicts... and finding crucial solutions for them."